The unions argue that current ID and batch recording delivers everything it needs to including protection against the spread of animal disease within the UK.
Farming leaders are angry about the proposed EID system, saying that the performance of electronic readers is often compromised by working conditions throughout the supply chain and will cost farmers up to 40% of their income without delivering any benefits to food safety or disease control
The NFU, NFU Cymru, NFU Scotland and the Ulster Farmers' Union have all expressed their serious concerns about EID for the nation's 33 million sheep. They say there are fundamental issues about maintaining individual ID and traceability for sheep that makes the scheme impossible to put into practice.
In a joint statement the union leaders said: "We have spent most of this decade lobbying against EID and we believe the current tagging system already works well in recording movements and offering control against animal disease problems in the UK.
"With UK livestock farm incomes forecast by Defra at between £5,900 and £8,700 we estimate EID will knock around 40 per cent off the farmer's income overnight. This is a significant percentage on what is already a pitifully low income.
"The UK sheep industry brings great environment benefits in its grazing pasture land and plays a significant part in the rural economy. This EU regulation has the potential to cripple what is one of the most efficient sheep producing areas in the world and could lead to land abandonment in some of the UK's most sensitive areas.
"It will have a negative impact on our competitiveness on the world stage and could compound the serious issue of global food prices facing us currently. We need to see changes to make the regulation workable or we risk facing an exodus of producers from the sheep industry."